1. Field of the Invention
The present invention relates to a display system, display apparatus, and method for controlling display system.
2. Description of the Related Art
Conventionally, a so-called multi-projection system is known in relation to projectors, in which a large screen is constructed by arranging a plurality of projected images in a form of tiles. In this system, in order to provide an inconspicuous seam or joint between adjoining images when the images are arranged in the form of tiles, a so-called edge blending process is applied, in which the luminance is lowered in a part of a display area of each of the projectors, followed by being overlapped so that the seam is hardly recognized. In this procedure, the overlapped area has a brightness corresponding to an amount to be provided by the two projectors. Therefore, a problem arises such that the overlapped area has a high black level (luminance level of a projected image corresponding to an input of the lowest (minimum) gradation value (“black” image)) as compared with areas other than the overlapped area. This problem is solved, for example, in Japanese Patent Application Laid-open No. 10-90645 such that the chromaticity and the luminance, which are obtained from a projection light, are measured, and the projection light is corrected on the basis of results of the measurement.
However, in the case of the conventional technique disclosed in Japanese Patent Application Laid-open No. 10-90645, it is necessary that a camera for measuring the projected image should be carried on the projection apparatus. Therefore, the cost is required corresponding thereto.